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RESULTS OF TESTS 



MADE IN THE 



COLLECTIVE PORTLAND CEMENT 
EXHIBIT AND MODEL TESTING 
LABORATORY OF THE ASSOCIATION 
OF AMERICAN PORTLAND CEMENT 
MANUFACTURERS. :: :: :: :: :: 




LOUISIANA PURCHASE EXPOSITION 

St. Louis, Mo. 

1904. 



RESULTS OF TESTS 



MADE IN THE 



COLLECTIVE PORTLAND CEMENT 
EXHIBIT AND MODEL TESTING 
LABORATORY OF THE ASSOCIATION 
OF AMERICAN PORTLAND CEMENT 
MANUFACTURERS. :: :: :: :: :: 




Richard L. Humphrey, M. Am. Soc. C. E. 

^4 [in charge] 



LOUISIANA PURCHASE EXPOSITION 

St. Louis, Mo. 
1904. 











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The Collective Portland Cement Exhibit and 
Model Testing Laboratory of the Associa- 
tion of American Portland Cement 
Manufacturers, and the Results 
of Tests at the Louisiana 
Purchase Exposition, 
St. Louis, Mo.* 

Richard L. Humphrey, m. Am. Soc. C. E. [in Charge.) 

Great expositions mark the progress made in the industrial 
world, and emphasize the advance in particular lines. The Louis- 
iana Purchase Exposition was no exception. Those who were 
fortunate in being able to attend the Exposition at Chicago in 1893 
and St. Louis in 1904 doubtless observed the progress which had 
been made in the branches in which they were especially interested. 
To those interested in cement, a very noticeable feature of the 
former was the absence of an American Portland Cement Exhibit, 
and the elaborate German exhibits of this material. This was 
naturally to be expected at a period when American Portland 
cement was hardly known and was regarded as of doubtful quality, 
while German Portland cement was universally used and was held 
in very high regard. The total consumption of Portland cement 
in 1903 was 3,264,801 barrels, of which 82 per cent, was of foreign 
and only 18 per cent, of domestic manufacture. In the decade 
which has since elapsed a great change has taken place in the 
production and consumption of American Portland cement. The 
production has increased 450 per cent., while the importations 
have fallen off about 73 per cent.; the consumption now exceeds 
26,505,881 barrels, and this country has grown from one of the 
smallest to one of the largest Portland cement producing coun- 
tries of the world. 



* Presented jointly to the Association of American Portland Cement Manu- 
-facturers and the American Society for Testing Materials Reprinted from the copy- 
righted proceedings. 

(3) 



It was quite appropriate that this remarkable growth of the 
cement industry in America should be fittingly exploited at St. 
Louis, and it was natural that this exploitation should be made by 
the American Portland cement manufacturers in a collective 
exhibit. Such an exhibit formed the gateway to the mining gulch 
of the Exposition and was one of the most attractive of the outside 
individual exhibits. The fact that there were no foreign cement 
exhibits worthy of note, served to emphasize the withdrawal of 
the foreign Portland cem.ent from the American market, resulting 




Fig. I. — General View of Building. 



from the development of the American Portland cement industry. 
In yet another particular was this collective exhibit noticeable. In 
1893 the American Portland cement manufacturer, while not 
openly hostile to the inspection and testing of his product, was 
nevertheless not a strong advocate and frequently rebelled against 
the restrictions placed on him by the testing engineer. Yet it 
was because of this continual raising of requirements which com- 
pelled the manufacturer to improve his product, that he occupies- 
a premier position in the cement industry to-day. We now find 
the manufacturer no longer the opponent but the firm advocate of 



proper methods for testing. This new attitude was shown in the 
equipment and operation of the Model Testing Laboratory in 
which was exploited the methods for testing cement proposed by 
the special committee of the American Society of Civil Engineers, 
whose report was distributed gratuitously. Only those who have had 
an active part in the erection of buildings and installation of exhibits 
at a great exposition can appreciate the vexatious delays occasioned 
by unforeseen difficulties ; this was particularly true of the cement 
exhibit. 




Fig. 2. — General View of Laboratory. 



It was originally intended that the work of construction should 
be carried on during the Exposition as a working exhibit. To 
secure greater advantages in an educational way it was subse- 
quently decided to complete it as soon as possible, but before this 
could be accomplished the Exposition was well towards its close. 
The buildings, and the installation of the equipment of the labora- 
tory and of the other exhibits were quickly comp^^^^ed and the whole 
placed in a working condition. 



6 



The completed Exhibit formed a comprehensive exposition 
of the Portland Cement Industry, comprising: 

1. A collection of the raw materials from which Portland 
cement is manufactured, together \^'ith samples of this material 
taken in various stages of manufacture, to the finished product. 

2. A collection of the various sands, gravels, cinders, broken 
stone and metal used in concrete, together with photographs and 
models of structures built of concrete in all parts of the world. 

3. A librar}' of books and files of the various technical journals 
devoted to cem.ent, mortar and concrete. 




Fig. 3. — View of Cement and Concrete Materials Exhibit 



4. A completely equipped model testing laboratory. 

5. A collection of machines for mixing and molding concrete; 
and, 

6. A collection showing the many forms in which Portland 
cement is used. 

The exhibit building, one of two permanent structures, which 
has been presented to and accepted by the Park Commission of 
the City of St. Louis, Mo., is an excellent example of reinforced 



concrete construction, and consists of three pavilions separated 
by intermediate courts and connected across the front by a con- 
tinuous loggia, the roof of which is covered with cement tiling 
(Spanish pattern) of a rich red color. This coloring, together 
with the red tinting of the ceiling of the loggia, relieve the general 
grey tone of the walls and forms an agreeable color contrast. The 
style, Spanish Mission, and the rough-finishvid walls are particu- 
larly well adapted to the use of concrete. 

As much interest was manifested in the finish of the walls, a 
description of the method used is added. The forms were re- 
moved at the end of twenty-four hours after casting and the out- 
side surface was then scrubbed with a soft wire brush, washing 
with a hose at the same time, — this removed the cement and sand 
from the surface, leaving the stone of the concrete prominently 
exposed and producing the effect of rough casting. The advan- 
tages of this method are, first the production of a uniform color, 
and second the prevention of the appearance of hair cracks by 
the removal of the excess of neat cement. 

The superstructure of reinforced concrete rests on a sub- 
structure of concrete, carried to a solid foundation, reaching in 
some portions a depth of i6 feet. American Portland Cement, 
Mississippi River sand, chatts (the screened tailings from the 
Missouri lead mines) and broken stone were used in the concrete 
in proportions of one part cement, three parts sand, and six parts 
broken stone for the substructure, and one part cement, two parts 
sand, and four parts chatts for the superstructure. 

The roofs, covering the pavilions, are of ferro-inclave con- 
struction, 3 in. thick ; consisting of corrugated sheet iron plastered 
on both sides with a mixture of Portland cement and sand. 

The walls are reinforced every foot, both horizontally and 
vertically, by J-in. round rods. The beams of 30-ft. span have 
2f-in. diameter round rods, in the upper and 2|-in. rods in the 
lower portion. For the 20-ft. beams J-in. round rods are used 
in the upper and |-in. rods in the lower portion. The stirrups 
are ij-in. wide No. 16 gauge iron. 

The interior walls were floated while green with a mortar of 
cement and sand, and subsequently tinted with rich water colors, 
the reception rooms being finished a deep vermilion, the laboratory 
a warm terra-cotta, while the exhibition room is finished in a 



8 

deep green. The ceilings are uniformly of a rich cream color. 
Between the windows, bordering the interior courts, are medallions 
of the labels of the various companies, cast in Portland cement. 

The south end pavilion was used as a reception room and 
office, and contained a reference library of books and files of the 
leading technical journals devoted to cement, mortar and con- 
crete. The north end pavilion served as an exhibit room, in 
which was displayed the collection of the characteristic raw 
materials from various parts of this country used in the manufac- 
ture of Portland cement, showing raw material in the various stages 
of preparation to the finished product. The coal used was also 
shown in the raw and finished state. In all three pavilions were 
transparencies of some of the Portland cement plants in this 
country. 

The various forms of metal used in reinforceing concrete, 
the sand, gravel, cinders, and broken stone, from all over the 
country, were on exhibition. Besides, there was a collection of 
photographs of work built of concrete, from all over the world, 
and of tests made to estabhsh the fire-resisting qualities of concrete. 

The wonderful growth of the Portland Cement Industry, the 
steadily increasing consumption of American Portland cement, 
and the decreasing consumption of natural and imported Port- 
land cement was shown graphically, while by means of maps a 
comparison was made between the plants in existence in 1890 
and those in existence at the present time. 

The central pavilion contained a thoroughly modern and 
admirably equipped testing laboratory, the finest that has ever 
been installed in this country. This laboratory was in daily 
operation, demonstrating the methods used for testing cement 
and concrete. 

The mixing and molding were performed on two especially 
designed tables, each of which is 7 ft. long, 28 in. wide, and 3 ft. 
high at the main portion; each end (32 in. above the floor) has 
a one-inch plate-glass mixing slab 2 ft. square. In the central 
part of one of these tables a galvanized iron pan 2 ft. square and 
6 in. deep was inserted provided with a cloth-covered wire screen 
top, and a wooden rack in the bottom |-in. high. The pan was 
filled with water to the top of the rack and the cloth was kept wet. 
The test pieces used in the determination of time of setting were 



placed on this rack and kept there during the test, being removed 
from time to time to make trial tests of the setting. The object 
was to maintain the test piece under uniform conditions during 
the test. 

The tension and compression test pieces, as well as those for 
the soundness, were kept in moist air for the first 24 hours after 
molding. For this purpose there was a moist closet, which con- 
sisted of a soapstone box 4 ft. wide, 18 in. deep and 2 ft. high 
resting on a wooden frame 30 in. high. The closet has a central 
vertical partition, and was provided with wooden doors covered 
with planished copper. The bottom was made water tight, and 
holds about 6 in. of water; the sides have cleats for holding four 
sets of glass shelves 4 in, wide, 22 in. long, on which were placed 
the molds containing the neat cement briquettes. At the bottom 
over the water is a wooden rack, on which were placed the molds 
containing the mortar briquettes. 

The test pieces were removed at the end of 24 hours, marked, 
removed from the molds, and for all tests for longer periods than 
24 hours they were immersed in tanks. These tanks were of 
soapstone, provided with running water and were arranged in 
tiers of three each. There were six tanks in all, each 6 ft. 7 in. 
long, 30 in. wide. One of the upper tanks is 30 in. deep, and was 
used for the storage of large beams and cubes of concrete; the 
remaining tanks were all 6 in. deep (inside measure). Each tank 
was provided with two inlet and two outlet pipes, by which the 
water was maintained at any constant level. An instantaneous 
gas water heater was connected to the supply so that the tempera- 
ture of the water could be maintained practically at 70° F. 

For the determination of time of setting and normal consis- 
tency there were two Vicat Needle apparatus, one made by Tinius 
Olsen and Company, and the other imported from Germany. 

For the tension tests there was a long and short lever machine. 
The former, made and loaned by Tinius Olsen and Company, 
of Philadelphia, was driven by an electric motor, and was auto- 
matic in the application of the weighing load; while in the other, 
made and loaned by the Fairbanks Machine Company, of New 
York, the load was applied by a stream of shot flowing into a 
bucket suspended to one of the levers, the slip of the clip on the 
briquette being taken up by means of a worm which operates the 



10 

lower clip, a feature which has added very considerably to the 
value of this type of machine. 

For the compression tests there was a 40,000-pound, hand- 
driven machine built and loaned by the Falkenau- Sinclair Machine 
Company, of Philadelphia, and a 200,000-pound electric motor- 
driven machine built and loaned by Tinius Olsen and Company, 
of Philadelphia. This machine was equipped with table for 
transverse tests up to 10 ft. clear span, and was provided with a 
ball and socket bed plate for compression tests up to 12 in. The 
former machine was new, having been built especially for this 
exhibit, at the request and under the supervision of the writer. 

The proper way for testing cement mortars or concretes is 
in compression, as it approaches more nearly the conditions of 
actual use. When we design structures in concrete, we disre- 
gard the tensile strength of the concrete, and figure entirely on 
the compressive strength, incorporating in the beam or column 
sufficient metal to take up the tensile stresses. Why then should 
we test cement in tension ? We will find the reason in practical 
rather than theoretical conditions. The average laboratory, or 
more specifically, the usual laboratory of the consumer, is not 
provided with a large fund for its equipment or operation. The 
usual machines used for tests of strength are the tensile testing 
machines, ranging in price from $90 to $200. The compression 
machines sell for from $800 up, besides requiring power for their 
operation. Their cost places these machines beyond the reach of 
all except the large permanent laboratories. The 40,000-pound 
machine, in the laborator}^ will sell for $300. It is to be hoped 
that under favorable cost conditions, compression tests will come 
into increasing favor, and in time supplant the unsatisfactory 
tension tests. 

It is an encouraging fact, and worthy of note in passing, that 
tests of cement are being regarded of much greater importance 
and are receiving correspondingly greater attention than formerly. 
This is unquestionably the result of the increasing and varied 
application of cement for constructive purposes, and under con- 
ditions which render the quahty of the cement of paramount 
importance. 

The most important test that can be applied to cement is that for 
soundness or constancy of volume, as it is of the highest importance 



] 1 

that a cement once set shall remain volume-constant. No en- 
tirely satisfactory test has been devised for this purpose. In the 
apparatus used in this laboratory the pats were placed on a rack, 
over boiling water, the surface of which was kept constant by means 
of a constant level bottle. The pats were maintained in an at- 
mosphere of steam at a normal pressure. No matter what the 
character of the water may be, the steam will be pure, and thus 
free from the objectionable feautres that may enter into the 
boiling test. 

The laboratory was provided with the usual standard sieves: 
Nos. loo and 200 for cement; Nos. 10, 20, 30, 40, 50, 60, 80, 100 
and 200 for sands, and with an analytical balance and scales, 
with the necessary metric weights, made and loaned by Henry 
Troemner, of Philadelphia. For the specific gravity determina- 
tions the Le Chatelier's apparatus was used. 

There was also a Bauschinger apparatus for measuring the 
expansion of cement, and the usual measuring devices for the 
various tests. 

In the rear of the building were the outside exhibits which 
served to illustrate a few of the many uses to which Portland 
cement is put, and some of the methods employed in mixing and 
molding. 

The flexibility of reinforced concrete construction was illus- 
trated by a cantilever beam exhibited by the Hennebique Con- 
struction Company of New York, and which was tested to 
destruction as described hereafter. 

Adjoining this cantilever was an exhibit of the Siegwart 
hollow reinforced beams, by John E. Olsen, of New York. 

The Trussed Concrete Steel Company, of Detroit, Michigan, 
made a series of test beams and erected a floor system, the latter, 
a combination of hollow tile and concrete beams, and also some 
columns supporting a beam, all serving to illustrate the "Kahn 
System". The tests of these beams and floor slab are also 
described hereafter. 

A floor panel between two steel beams, resting on concrete 
piers, served to illustrate The Roebling Construction Company, 
of New York, system of fireproof flooring. 

The Truss Metal Lath Company, of New York, showed 
a section of partition, illustrating the use of the Truss metal lath. 



12 



Ornamental work in cement was illustrated by the Algonite 
Stone Company, of St. Louis. The exhibit comprised a porch 
consisting of two columns and two pilasters, supporting a pedi- 
ment and roof; these pilasters and columns were connected on 
each side of the porch by a balustrade. Several steps led to the 
porch floor. They also exhibited a Corinthian column cap, 
and a cap for a pilaster and other forms of artificial stone work. 

The National Art Stone Company, of Chester, Pa., displayed 
an ornamental mantel and column ; the feature of the exhibit was 
the extremely low percentage of cement used. Samples were 
exhibited containing only three, seven and ten perecent. of cement, 
and ninety-seven, ninety-three and ninety per cent, of sand. 

The Art Mosaic Tile Company, of St. Louis, displayed mo- 
saic work in Portland cement; they had a fireplace, a kitchen 
sink, and flooring tiles. 

The Vulcanite Paving Company, of Philadelphia, showed 
a section of granolithic pavement, and a section of steel-bound 
concrete curbing. 

Concrete railroad ties were exhibited by Casper Buhrer, 
of Sandusky, Ohio, and Frank Ford, of Albion, Mich. The 
former were made of old rails with the head bedded in the con- 
crete and with the flange up, the latter serving as the bearing 
and means of holding the rail in place. They have been in 
service in the Lake Shore and Michigan Southern Railroad for 
over two years. They have also been used by a number of other 
railroads. 

The Ford tie was in two pieces, connected by a rod insulated 
at the connection. 

Reinforced concrete fence posts were exhibited by H. T. 
McCarthy, of Detroit, Mich. 

The reinforced concrete burial vault, shown by George A. 
Rackle and Sons, of Cleveland, Ohio, marked a new feature in 
burial practice, having advantages over the wooden casket 

The Kielberg pipe of Danish manufacture (made with a 
hydraulic press) was exhibited by F. L. Smith and Company 
of New York City, the American agents. The pipe was of 
excellent quality, and stood the long transportation without dam- 



age. ^ 



13 

The hollow building block machines were exhibited by H. 
S. Palmer, of Washington, D. C, the Cement Machinery Com- 
pany, of Jackson, Mich., and the Burlington Block Machine Com- 
pany, of Burlington, Iowa. These machines were in operation 
daily, demonstrating the manufacture of cement blocks. 

The two-piece block was exhibited by the American Hy- 
draulic Stone Company, of Denver, Colo. Walls of various 
thickness from three inches and upwards were shown. 

Cement brick and cement paving tile machines were 
operated by A. D. Mackay, of Chicago, 111.; while cement roofing 
tile is displayed by the American Cement Tile Manufacturing 
Company, of Wampum, Pa.; Brock Bros., of St. Louis; and 
Furman Construction Company, of Detroit, Mich. The Brock 
tile is plain, the American is made corrugated, diamond- shaped 
and in the four-foot plain form, while the Furman is diamond- 
shaped. 

The Municipal Engineering and Contracting Company 
and the McKelvey Concrete Mixer Company, of Chicago, had 
exhibits of concrete mixers. The former was a cubical mixer, 
mounted on wheels, and was complete with boiler and engine 
for operating. The McKelvey mixer was a hand-driven barrel 
machine. 

The limited time available after the completion of the exhibit 
was insufficient for the execution of any elaborate series of investi- 
gations. It became necessary, therefore, to concentrate the work 
on such tests as would be productive of data of the greatest value. 
The tests made were of two kinds: those made in the laboratory 
and those made among the outside exhibits, consisting for the 
most part of full size concrete beams and floor slabs which were 
loaded to destruction with pig iron. The work in the laboratory 
was confined to illustrating proper m.ethods for testing cement 
and to investigations of the comparative value of the various sands, 
gravels, and broken stone used in some of the principal cities of 
this country. 

Inasmuch as the exhibit was the joint work of some forty Port- 
land cement companies it was deemed undesirable to advertise any 
particular company either by permitting individual exhibits or 
by the use of a particular brand. The building was built with 
cement which was a mixture of four brands of Portland cement. 



14 



readily found in the St. Louis market. The same policy was fol- 
lowed in the cement used in the laboratory tests; in which case a 

thorough mixture was made of five 
brands, which gave a standard 
Portland cement of sufficient quan- 
tity for the entire series of tests. 

It is a rather curious fact, that 
the average of the tests of the mix- 
ture of the five brands was higher 
than the average of the tests of the 
individual brands. The result of 
these tests is summarized in Table 
I, page 1 6. The variations in 



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Fig. 4. — Diagrams of Results of Tests of Cements and Mortars, Showing 
Effect of "Personal Equation." 



15 

the results of these tests are due to two causes: (i) Changes 
in the quality of the cement due to atmospheric conditions, 
and (2) changes occasioned by the variation in the "personal 
equation" of the operator. Two men made the same tests 
simultaneously, using similar apparatus and methods. The effect 
of the "personal equation" and other changes is set forth in 
the diagrams Fig. 4;* the ordinates being the successive tests 
as made, practically, at daily intervals. These men were inex- 
perienced in the beginning and it will be noted in the diagram 
that while the results were far apart in the beginning they became 
more concordant as experience was acquired. 

In the comparative tests with the standard cement, of sands, 
gravel, and broken stone it was only possible in the limited time 
to test those from the following points: Berkshire, Mass. ; Cleveland, 
Ohio; Cowe Bay, Long Island, N. Y.; Chicago, 111.; Dallas, 
Tex.; Kaw River, lola, Kan.; Philadelphia, Pa.; Plum Island, 
Boston, Mass.; St. Louis, Mo. 

The results of these tests will be found in Tables III, IV, V, 
PI. I, opposite page 16, and diagram Fig. 5, page 17. A study of 
the latter is quite interesting in that it shows the relation between the 
size of the particles and the percentage of voids. The tests seem 
to indicate that the smaller this percentage the greater is the 
strength of the mass ; this percentage being dependent on the size of 
the particles. Where the particles are well graded from coarse to 
fine, the percentage of voids is reduced to a minimum. This was 
found to be true of the unscreened sands and gravels, the highest 
results being obtained with the sand or gravel containing the 
least percentage of voids and showing the best gradation in the 
size of particles from coarse to fine. 

When this material is screened to one size as 20-30 the per 
cent, of voids and the strength become practically the same, re- 
gardless of the strength previously obtained with the unscreened 
material. In this particular it apparently matters not what the 
geological origin of the material is, provided it is not undergoing 
further decomposition. It is also observable that the specific 
gravity of the sands and gravels is practically the same. 
An examination of Table IV will show the very small percentage 

* Acknowledgment is made to the Engineering News for the cuts used 
in this paper. 



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riNC 


NtSS 


TIME OF 


SETT1N6 


WMTER 


TENSILE STREMCTH POUNDS PER SQ.UARE INCH 


Rcsioue IN sieve 


IN MINUTES 


NE-AX 


SAND 




NO- too HO zoo 


INITIAI. HARO 




1 DAV 


AvERAee 
iNOi- ^rw- 


7 DAYS 


avcrage: 


28 DAVS 


AVERAGE 

KOI- ICCH- 


7 DAYS 


AVCRACE 


2eDAY8 




A 
A 


S 83-!2C-«W- 

1.16 1 as-so 


27'i- SlO- 
286 -436 




lie l>l 117 
142 114 133 


"« .26 
133 , 


532 S47 S50 
S31 579 '»65 


^» 336 

J2e 1 


670 68^ 793 
690 730 69o 


712 
700 


706 


165 leo I70 
165 ISO 126 


>*8 ,5B 
147 


232 260 255 
277 295 263 


^262 
275 


B 
8 


880- 2&9<«- 

<» 00 1 «6.e5 


69- /lO- 
62 120 


20 'r 


**♦ 20s 220 
<2«272 2S0 


"°23y 
2SO 


591 602 6I& 
64 1 650 669 


609 
659 


^28 


790 756 776 
743 721 


77b 
729 


788 


287 266 270 
259 293 244 


"^;26. 

262 


437 423 396 
397 395 380 


"'^ 401 

397 


C 
C 


/o 00 


2a48 

46.30 


£63- i 435- 

2 15 ! 435 


2a 
20.0 


(12- IO> 1 10 
irf IZO |S3 


'^°!,27 

123 


639 626 S90 
595 5«0 696 


*'S 6IO 
604, 


959 974 739 
8S2 965 104 


824 
874 


849 


237 2*7 230 
190 191 2Z6 


202 


382 S72 AZZ 
345 358 562 


^^374 
3S6 


O 

o 


8'J'J- 

8.40 


Z4.30 
26.96 


40- 
■46 


al- 
ias 


20=?, 
20'4 


ai6 £^7 231 
24« 253 250 


231 
250 


241 


S^S 622 590 
572 S70 595 


5*^ 582 
596 


673 721 778 
685 727 675 


724 
696 


710 


260 274 280 
262 233 295 


'■" *»7 

263 


345 381 374 
413 393 32 


967 
375 


371 


E 
E 


4.6<»- 


22.33 
2(.SO 


35- 


265- 

280 


20^ 

20 'a 


lis 196 fS6 
23«2a/ 226 


/16 
226 


211 


S42 545 597 
520 595 .530 


"' 553 
545 


690 670 631 
640 673 671 


664 
66/ 


663 


220 211 208 
/70 217 /87 


2'9 2W 
191 


317 335343 
310 291 280 


332 

294 


813 


AveRAac 
AvniACC 


8.64 
8)9 


25.34 
2 53«» 


(35 
|4S 


Z18 


20 '4 

?0'4 




196 


109 


583 
580 


582 


740 
73« 


737 




234 

213 


£24 


952 

337 


94B 




STAHOtJS) 


7.7<» 
7.75 


24.35 
2S60 


ISO 1 314- 
|5I 332 

i 


20.0 

2ao 




2 74 
2SO 


2 77 


621 
623 


622 

1 


761 


770 




263 
240 


2SI 




991 
368 


980 





Table I. — Showing Results of Tests of Five Brands of American Portland Cement and of 
Samples Made From a Mixture of All Five Brands. 



SAMPLE 
NUMBER 




AREA 


coMPRessi vc 

STRENSTH IN LBS 


REM AR K S 


ASE 


_ WEIGHT 

Proportion, pcr 


PCR 
L^LTIMATT,^. ,^ 


I 


60 

DAYS 


|3«?.S8 


3 5.2 5 


58500 \(cS'\ 


SUSHTL.Y SPALLED AT EDGES. 


2. 




1 CEMENT 143.87 


35.25- 


ss«?jo noo 


DO. 


3 




ISAND /43.IO 


35.15 


68500 1943 


00. 


4 




5 CrtATTS )43.87 


3fe.OO 


7035-0 19 54 


DO. 


S 




143.36 


35.33 


48000 1 35«? 


DO. 


6 




144-06 


3563 


64 2 50 180 3 


DO. 


AV6 




143.04 


35.42. 


61585 /740 




7 


00. 


1 CEMENT /43. 18 


35.84 


2«?450 8 22 


CORNERS SPALLED. 


8 




2 SAND 143.52 


36.00 


27210 75"*? 




*? 




4 CHAXTs 143.87 


36 00 


33450 929 




/O 




142 4Z 


36. 00 


30SOO 858 




i/ 






142.47 


36.00 


3112-5 865 




12 






I4S88 


36-0 


30500 848 




AVG. 






143.44 


35.*l-7 


30439 847 




13 


00. 


1 CEMEWT 


I46.70 


34.76^ 


3020O 870 


ONE CORNER SPALLED. 


14- 




2 SANO 


/4S.II 


3S.62 


2 7 880 783 




15 




4 CMATTS 146.52 


3563 


55P50 /57*? 




16 




147.62 


36- 00 


49 100 / 3 64 




17 




146. 6<? 


3S.63 


407OO 1 142 




le 




145.73 


36. 00 


35200 978 




Ave 




/46.2 3 


35. 6/ 


39722 1 M*» 




H 


DO. 


i/4.»0 


22.24 


<4550 654 


VERY BADLY SPALLEO TWO CORNERS. 


ZO 




t CEMENT l;i2.«jo 


36 00 


I9o50 530 




21 




Z SANO 


/I3.4I 


33.78 


I£r900i 47 1 


VERY POROUS SPALLED ON COSES OF FACES. 


az 




4 CINDERS 


ri2-73 


35. 9 


22750 


62 


SPALLED SUeHTLY AT EDSES. 


23 






lis. 20 


33.25 


I9000 


^7 J 


ED6CS AND PACES SLieHTLY SPALLED 


24 






113.72 


3fc.OO 


19500 


542 


SLIGHTLY SPALLEO 


Ave 






113.36 


32.86 


18458 


565 




Z5 


DO. 




I40.I8 


36. 00 


59400 


1650 




26 






/3*!.«?7 


35.20 


5 09 50 


I450 




ar 




1 CEMENT 


j4a.<T7 


3S.2S 


65650 


1862 




26 




2 SAND 


(41.80 


35.2 & 


74 350 


2052 




a<\ 




4 CHATTS 


14 2.21 


35.25 


65250 


185 1 




30 






140.33 


36.00 


588 


16 1 8 




Avs 






141. 10 


354*1 


4>28iO 


»747 





















Table II. — Results of Crushing of Cubes Made From Concrete Used in Constructing 

Reinforced Beams. 















name: 


LOCATl 


BERKSHIRC 


BERKSHIRE 


CUEVEl-AfNtO *» 


CLEVELANI 


CI_EVEUA^aD ^-3. 


'• 


COW BAN' 


NEW VOF 


JERSEY GRAVEL 


PHILADEL 


KAW RIVER 


lOLA KAI 


LIME SXOIME**! 


ST. LOUIS 


LIIS/IE SXOME«2 


■• II 


MERAMEC RtVER 


•• II 


MISStSSIPPi RIVER 


It 


PUON/1 ISLAND 


BOSTON r 


XEX/».S 


DALLAS T 


BANK WASHED TORPEOfl 


CHI6A60 1 


LAKE TORPEDO 


•« 


BANK SAND 


PHILADEL 




AVER/KC 


Table III. — Specific Grav: 




NEA.- 


(slAME 


1 DAv .r^":ti 


T DAfS 


BERKSHIRE 


716 131 111 
133 136 130 


117 
133 


130 


551 51£ to: 
606 SOB SB- 


CLEVELAND • 1 


3-7S 351 
314- 390 


3C3 
3 SI 


3sa 


&67 674- &«? 
691 675 70S 


CLEVELAND 'T. 


1-73 193 
30A 33A 


163 

319 


30l 


633 566 S6< 
S56 S75 &4« 


COW BAY 


lae 307 
30t 170 


137 
166 


193 


616 691 631| 
63^ 610 S7e 


Kaw River 


15-7 ISO 
lis 130 


1S3 
113 


141 


595 S6e 614 
655 640 68 S 


LIMESTONE* 1. 










LIMESTONE. •!. 










MERAMEC 


131 1«S 

313 333 


169 
316 


309 


S9A S95 611 
603 633 eai 


MISSISSIPPI 


305 19-3 
303 3AT 


199 

316 


314. 


653 6IO 611 
S63 571 669 


PLUM ISLAND 


176 lae 

14.1 l>tS 


161 

7.*3 


1&3 


&71 646 fe4< 
SSI S70 639 


TEXAS 


l«5 I90 
105 XOb 


193 

lo« 


199 


641 6-»9 65i 
616 675 571 


WASHED BANKS 1 
TORPEDO J I 


16 S 1S3 
l«l 1S3 


169 
171 


161 


595 546 64=1 
61S 643 7 IS 


LAKE TOBPEDO 


173 310 
333 301 


1.97 

316 


306 


571 630 6se 
666 S4I 641 


AVERAGES 




17A 

leo 


177 




Table '. 


natvie: 


1 


01 


■7 OA.' 


'«'S 


BERKSHIRE 


1-4.25 less 
\-i.-S.S liVS 


I5-4.0 
\25o 


CLEVELAND*! 


I2VS l2»o 

i-iSo caeo 


1278 
1255 


CLEVELAND** 2. 


I308 CiftS 
1275 »3VS 


I2S7 
I32S 


COW B/KY 


28SS 2703 
12*5 l3-*3 


271* 
I214. 


Kaw, River 


l^oo 1^27 
I6*J8 leoa 


1263 


LIMESTONE"! 


l4.ao 1.4^3 


I3ev 
I't-i'a. 


LIMESTONE** 2. 






MERArvlEC 


I72.S IG23 
l-aSO 127.5 


1A7S 
1263 


M>SS\SS\PPI 


IISS \2.1G 
I^Sa »2So 


1302 


PUVJNA \SLANO 


ISOO I4.00 


14-SO 


TEXAS 


13o lo'lS 


laaa 
IOI3 


Washed bank torpedo 


His I08^ 
loss liSo 


1131 

lies 


JEWSEV GRAVEL 


I7S8 IS-J^ 
IIOO |070 


172.7 
1135 


PHVUA. BANK SAND 


icao I220 

'088 *^5o 


(■xoo 

lO \'\ 


AVERAGE 




1 






T. 


^.BI 


..E 


V- 



50 
20 
10 

0+ 
30 

20 

10 


40 

30 

20 

\Q 







NAIS/1E. 


LOCATION 


'iS^"^ 


"<"" 




-.-.s- 


RC^ARK. 




-^o 


3° 


■*° 


5o 


CO 


lOO 


aoo 


"i'io 


CLEIVEUAMD ** 1 
CLEVELAND "i 


CLEVELAND OHIO 


"^^fe 


"aiM 


"^^1 


t:;: 


:^,:? 


;-\ 


tl 


4-.I 


\- A 


'- 


,.c 




BR-oJ'^- 


COW BAV 
_vJER5EV GRAVEL _ 


NEV^ VORK. 


Isl 


3^^ 


io 


5.& 


8.& 
14.0 


■2.0.6 


I7.G 


^2 3 


R =i 


.1;^ 


;.t 


■5.1.4- 
:4S 


VeLowisV 


LIME STOrviE** 1 


ST. LOUIS MO. 


i767" 


3"7. 5 


34.7 


8-S 


<5 7~ 


e* 


3.-7 


-*-S 


:jo.3 




~PL U N/l 1 S L A rM D 


BOSTON fvlASS. 


a.e? 


i',l 


e.c 


5.0 
G.I 


■A. 3 


3. S ' 


t; 


::4 


LIGHT VELLOW 

CHOCOl-ATt Cot-OR 


LAKE TORPEDO 
BANK SAh4 




!:1 


34-,=* 


O.S 


KS 


S.6 


IS.l. 


■20.3 


13.1 


1.3. 


1.3 
5.G. 

O.I 


0.3 




YELLOWISH BROWN 
BROWN 








Jfc-i'l 


"•"^1 




i^-a 






'S.B 


-"V.? 


^J, 


3.1 


5.S 


AVER^ed 



Table III. — Specific Gravity, Percentage of Voids and Granulometric Composition of Variou 
Sands for Cement Mortar. 



TENSILE 


: STRENGTH IN LBS. PER SQUARE INCH | 


NAME 


1 oov S™i 


1"^' "rv.% 


»»»«s -i:™". 


,„„...„.„_ 


"-V3 -"•.■•. 


l.OAVl -■■.-.■. 


'"-^ "■."•.-. 


,06,3 6.J,... 


3.0AVS •:r'.v. 


'"" ::■.".•.■. 


,„^,, .™6. 


3.»»y. -;-:;, 


^^^^^T^S-ri 


■'"?"'" 


u; ^" ^ 


m 


.=0 




"1 


... 


I" In ,™ 


'7^, 


77. 


""", 




3.7 


ll? 3« 3« 


1" 


33, 


";jS"t 


H 


>,. 


tU "' 


"I 


6,. 


,3. ,3. ,3. 


,3. 


.33 




3,. 


3,3 


.»>3.. 


3.3 


.., 




















CLe«i>~o., 


r° n 


J5* 


»• 




«o 


.^ 


•;° "^ ;^ 


"1 


»„ 


^« °" 


lit 


.63 


7" ,'" U^ 


7.3 


"' 


.ll.^t" 


"I 


.«. 


>" 3" 


III 


3.6 


r.r ;;i ?" 


,t; 


35, 


3« «r 3« 




3,. 


I" I" 


"i 


37, 










■~ 








^, 


eLEVCL*Nt> ^ 


\Z"l 


;°,' 


"" 


Sl°"^ 


:," 


'~ 


*;',»?.» 


^ 


7,7 


;;i "7" 


Zl 


»3 


1*5 71. «? 






\"^lll"l 


». 


3.6 


337 63,' 


:,3 




^M TS U'. 


III 


30, 


>« ."j" ". 


IV- 


3,7 


«3 Ul 


?Ii 


37. 


^« '." Ill 


"3 


336 


"I Itl U° 


",' 


3.3 


;« .':; 


3- 


. 


sot ino 


i.a 


3.3 


Mt «6 576 


611 


"' 


161 «S 7« 


7Bi 


736 


.« .77 


33. 


*«■ 


76. 733 377 


M3 


33. 


356 377 53. 


i»7 


36. 


III 3^ 


i'-^ 


3.3 


^6 7« ^ 


III 


35, 


35I s'3 "3 


III 


3*. 


«o stl 


5 33 


333 


ra. "3 373 


in 


317 


U' "'^ 


iM 


,M 


3I7 »^ 


in 


3U 


KAW RiVEF? 


'« III 


«i 


»., 


">^t^ 


^« 




7l\ ^ 7™ 


7s'o 


7.7 


"3 "^ 


"^ 


.3= 


III I" 7" 


-.6* 


73. 


in *" III 


•^ 


«., 


:^;^; 


til 


.53 


3« 3!. m 


mi 


373 


lit MO 3" 


"i 


3.0 


53. 337 


i" 


37, 


III IT^ in 


III 




III, ttt III 


*" 


3.. 


..660, 


;~ 


3.. 






LIMCSTONC'I 












































I'ss.s; 


I" 


373 


1^30*635 


2» 


>., 


;~;^ 


!" 


630 


",' "' im 


731 


35. 


"I mi u. 


,.s 


»n 


j;; ;;; 


IS 


«, 


"""T?''^"^ 












































^sis 


;" 


36. 


"Sl^iS 


"0 


..7 


^To" 


t?.* 


.03 


i'°, 3,~ ;;i 


IV 


3,3 


'.U "I iz 


," 


c 


^. ;» 


MBP^AMW 


SI «i 


s; 


30. 


";"."", 


t» 


'" 


m ;i\ ^" 


... 


7.. 


;« i'^ 


S' 


.6, 


UIm^™. 


i" 


3.0 


Zl I" III 


3I* 


5.3 


"'"3" 


"r 


«.. 


3" 3" St 




367 


I™ U^'i 


"' 


3, 


^33^ 


s 


33. 


Jii.n". 


363 


37, 


U\ «i HI 


7^ 


3., 


3oi 3" 


.'," 


35. 


"'"'?'"■" 


3^3 »*T 


."i 


'" 


Ill l!° Si 


tii 


ti. 


■T30 '.a Tt.O 


'^ 


73. 


lU 7°5 


7." 


7., 


1^3 "3 M3 


«i 




'"Jttjs 


t" 


36. 


^°, •" 


*;; 


663 


injSui 


iz. 


366 


1" "0 "' 


3^ 




3^367 


337 


366 


3!' '«• 33' 






l*t HI iti 


"0 


3.. 


1" I" 


i^V 


^y" '*'^'^'* 


'™ ^ 


t". 


«3 


3^ 5^*M 


tJo 


»« 


7"";;?! 


'il 


7.3 


I"S« 


Sit 


.U 


;" ;" I", 


ill 


363 


iti 3?r 3" 


vn 


37, 


)^i*n 


"L 


66, 


'« i« r.t 


"3 




^3^"' 


vn 


33, 


"iJ^ 


V*. 


33. 


32.«ll" 


lil 


3,3 


5~ Li f ; 


^ 


30. 


"i III 


TEXAS 


«l SS. 




,» 


t" "' J" 


t'r 


»» 


n° '■* In 


III 


7« 


"i 7^ 


™i 


7.3 


I" S'. "s 


I" 


7.3 


^r a iix 


"S 


37. 


'" 6^ 


'« 


63, 


III IZ III 


;" 


3.6 


ttT t>3^ 


'" 


6,6 


^*" 


™ 


6.3 
















i« 


"o"."^") 1 


i" III 


m 




'"t*s*^ 


<m. 


™ 


iz ™ ;« 


III 


•77, 


"7 ™3 


S^3 


»3 


"I Ut "' 


III 


363 


III I" ".° 


;~ 


3». 


Zl t" 


:;; 




7- "3 "I 


;i; 


3.3 


*;; ;^ '^\ 


3" 


5.7 


3«1^ 


^.i 


63. 


70I ixi in 


"* 


33. 


■"U'.t" 


III 


5.. 


Itlltl 




III S 


"a 


»«. 


;« ™ tr 


tn 


... 


III .0° ^0 


''ill 




.73 "73 


87* 


..0 


"7 ^T 3" 


T.l 


36. 


"' " 173 


3" 


3.^ 


TX 111 




6,. 


".t J™ ^'3 


•;; 




Itt III IV, 


3» 


..J 


lit I" 


",' 


63, 


ll\l"lV, 


;;; 


33. 


'r.t',!".','. 


I'.l 


>„ 


III "I 


lit 


.36 


AVER*0£S 




;r. 


- 




«; 


'» 




,™ 


7,0 




*,*; 


.« 




111 


3., 




■" 


3.. 




™ 


.3. 




l» 


36. 




;," 


"• 




;," 


... 




"' 


.3, 




U: 


3.. 




IV, 





T.^BLE IV. — Comparative Tensile Strength of Mortars Made of Sands of the Composition Shown in Table II. 







ZI 


IZ 




COMPRES^IVF 




SXRENGTM. 


^ IN 


LBS. 


PER 


50. 












— 







— 





BERKSHIRE 

CLEVELAND-! 


T^f^ 


I5-4.0 


E 


27.58 2653 


YS 


;;i^ 


3*40 2S5S 


iZHj 


2247 


7 PA 

14J» I47J 


^_ 


541 






^TT 


iSf!S! 


14^4 


^ 


SCRKEN 

1 


-P TO -20-30 

^BO^VS ^ 2MOJ: 


TMa 


= 


COW BAY 


1^75 1373 
l»7S 13.63 


P32S 
2714. 


=;;? 


3SI3 3738 


362« 


s;^ 


24G3 3Gao 


4001 


2452 


S3% Sas 


s 


loGe 


28B8 363^ 


ilS 


3S»7 


2-«S3 2483 
3.S78 3310 


'■*«8 


3137 




|i||- 


1171 


^'_P?2*r'_* 


IU5 


,>„- 


3428 3450 
2*75 2S6S 
2380 3 3«1 


J47n 


2412 
24*4 




Is^s nil 


ies3 


i-*sa 


2.I-38 3 lis 
(■ISO aooo 


n7s 


5=S3 


zlva 2^0 


J^ 


2483 


iGsa isoo 


1485 
'3*14 


IS40 


J<SJI,7i 


33n 


3,00 


24.5 2^75 


^iST 


ji^ 


I300 i4*a 


1^7! ,^- 






,«<, ,^3 


ilT-i 


'^" 


5:175 aaas 


7^a" 


""' 


2SS8a53o 
2615 27'»3 


38*-* 


27JS 


2CC3 2400 


3S31 


25-57 


aa3« 30I0 


"" 


34eo 


37.'nf^ 


3«7i 


3704 


TS«-,Ts3 


T--J7 ;,,;,, 




3 3^ J 2-4-50 


3317 


_ . ■■ 


















sis Hso 




lOos 


1113 M«B 


l'.7° 


1^ 


,6»-S .678 


I^ 


.703 


T^iTosV 


'°"^oiS 


^:^Hlf£t'"". 


'27Tfli 


2q«t_ 

33 7« 

28So 


210^ 
2 704 




,«o^:.„ 


t-aca 


3«1 


zcae 2S« 


aeo'^ 


3o46 


3C«i3575 


si 


^3^5 


lao:^ '.i'so 


13:1s 


i2iro 


""f,'<^ 


3a'»5 


2425 3.-288 


If?,' 


»343 


1X3^ IVls 


'l^v'^-^' 




,3 


244 


ll?3 ^S 


331* 


.450 121 


i4e<f 


ISIS 


34CLO 4.1 2.S 


5"' 


377.5 


38>S 4158 Aooe 




SSo'.'oSo 


"ri?ti;^|7 


iiiiKtijKB^^" 


PLUN. .SLAND 




•^e7-s_fMiL3 




t°ls ^"^^ 


3.S6 


;;«« 


p'ila sk\* 




1043 


11" lilt 


Iss^ 


,se4 




3«7 


llS^ I703 


TEXAS 

WASHED BAMKTORPEM 
wIERsev GRAVEL 






,7" nil 


10. i '"* 


f 3 *5 267S 




l^l jJL" 


"" 


'loo 1748 


>e24. 


I4-4G 


alat I,"," 


3c" ''" 




jcn 






; 1"- 


1^^ "^^ 




3G^ \isl 


33. u 


I'o^iVs- 


4ie 

4J3 


S54 


aJ'so li^l'ltl!-"^' 


rAS^ iS*3 


I'l^^ 


306, 


T^kT^'J 


TiSf*-^ 


""»•'>'<■ 


2436^^^'* 


1,00 ,07o 


135 ''^'^' 


aGioi^'slalTJ^'"^ 


301^ frili^r^Cj'^^'''" 




'^^^llSlS 


^■^^'zars 


Ui3 1.7. IIGt „^j 


T.l Z\ 


Av£r^3. ■ 


■^ 1 1.36A 


'^°"""'l 


5 


iS 


"""- 


1^ 


2e3« 


4SO 4JS 


^ 




77? 


'loo 


^ 


2£57 


4?I Ss 


||, 


U&l 


^ 


iill. 



Table V — Comparative Compressive Strengths of Mortars Made of Sands of the Compositions Shown in Table II. 



30 
20 
\0 









/ 


\ 














/ 


\ 












/ 






\ 










/ 






\ 








/ 


Voic 


is 3 


l5°Jo\ 


















^ 



































/ 


N 


^ 




\ 








/ 








\ 


\ 








Vol 


did 


54. C 


}% 


\ 
















\ 


-^ 


. 



































\ 


s. 
















\ 




y 




\ 








Voids 


89. 


6%\ 




















\ 



Plum Island. 



Texas 



Washed BanK Torpedo 



30 

20 

10 






^ ^ 10 20 30 40 50 80 100 200200+ 10 20 30 40 50 bO 100 200 200+ 10 20 30 40 50 80 100200 200+ 



C Limestone No.l. 

3Or 


20 

1 10 



Limestone No.2. 



Meramec 

























^ 


\ 












/ 




\ 








/ 










\ 






/ 


Voids 


37.^ 


t'M 


\ 
















\ 




-^ 

















































/ 


\ 








/■ 










\ 










1/(7; 


fols 


51.50/0 


\ 




















X 


^^ 



Kaw River. 
































/ 


1 














J 


/ 


\ 














/ 




\ 








^ 


'"^ 


^oid 


f ^ 


3.3 


% 


\ 


















\ 



10 20 30 40 50 80 1O0 20020O+ 
Mississippi . 

i30 



20 













/ 


\ 
















/ 


\ 














/ 




\ 






- 


- 


"vy 


^-^ 


/ 




\ 






ids 


34£%\ 




















N 


^ 



Jersey Gravel, 



\ 
















\ 
















\ 
















\ 


V 


Vo 


10(5 


31. 


/(^/a 






\ 
















N 


N, 


















\ 


















'■V 


•\ 









Lake 


Torped 


0. 














































/ 


\ 
















/ 


\ 














/ 






\ 












/ 






\ 










/Vo/c 


is I 


\d.O 


% 


\ 








/ 










\ 




___ 



10 



40 



30 



20 



\Q 



JO 20 30 40 50 80 100200200+ 10 20 30 40 50 80 100 200 200+ 10 20 30 40 50 80 100200200+ 10 20 30 40 bO 80 100 200 200'^ 
Philadelphia Bank Derksinire. Cleveland No.l. Cleveland No.2. 

ENS. Niws. S-t Ci r-\ d c*. Y~ cii 5ieve£>. 

Fig. 5. — Diagrams Showing Granulometric Analysis of Various Sands for Cement Mortars. 



i8 



of fine material passing the number 200 sieve and even of 
material designated as "silt" except in the case of the two lime- 
stones. This fine material in all cases being inorganic, and should 
not, therefore, be classed as "loam" — a term in common use. 
The term "loam" is a much abused one, is rarely ever used cor- 
rectly, as "loam" properly so called is a vegetable mold and has a 
decided weakening effect on the strength of any material in which 
cement is used as a binder. Fine inorganic material, if not pres- 
ent in excessive proportion, enhances the strength of mortars or 




Fig. 6. — Views of Reinforced Concrete Beams 1,2,3 ^^^ 4 After Failure 

concretes, as it tends to lessen the percentage of voids thereby 
reducing the quantity of cement required to fill the voids. 

In addition to the above tests, four experimental beams were 
tested in the laboratory; three of these (two of rectangular and 
one of T-section) were made according to the Hennebique system ; 
and the other, also rectangular in section, according to the Kahn 
system. The beams of rectangular section were made under 
identical conditions and were designed to CRrry the same load 
using the same percentage of steel reinforcement. These beams 
were made in the open air and were not wetted after being made 



19 

and the forms were removed just before the tests were made, at 
the end of 60 days. The beams remained in the open air during 
that time and were not moved until tested. 

Test cubes were made of the concrete from which the beams 
were cast and the results of these tests may be found on page 1 6 , 
Table II from 25 to 30 inclusive. 

Fig. 6 shows the condition of the beams after testing; the pho- 
tographs are not, however, sufficiently clear to show the location 
of the hair cracks. The poor quality of the concrete which will 
be alluded to later, caused the beams to fail without developing 
the full strength of the steel in tension, although in both the Henne- 
bique and Kahn beams the compressive resistance of the top of 
the beam was materially increased by the steel reinforcement. In 
the latter beam the results would probably have been higher had 
the top reinforcing bar run the full length of the beam, as it will 
be observed that the concrete failed around the ends of this bar. 

The following is the result of the tests of these beams in the 
order in which they were tested: 

IS I :. :..--3;::z:::zzz:::::z::;;x^^ 

"fii'is^- lo'o" - ^ H/p. 

Beam i, Kahn System. — Length over all, 11 ft. iif ins.; clear span, 
10 ft.; breadth, 6^ ins.; depth over all, SJ ins.; depth to center of steel, 
7i ins.; compressive strength concrete, 60 days, 1,747 lbs. per sq. in.; 
weight of beam, 593 lbs.; mixture, 1:2:4; reinforcement in top, one ^-in, 
Kahn bar 9 ft. long; reinforcement in bottom, two J-in. Kahn bars 11 
ft. I if ins. long. 

Steel in tension i-59% 

Steel in compression 80% 

Total steel 2.39% 

Loads. Deflection, 
lbs. in. Remarks. 

1350 3-32 

2350 1-8 

335° 5-16 Crack appeared on right under end of top of rein- 

forcing bar. 

4350 3-8 

5350 15-32 Crack appeared on left under end of top of rein- 

forcing bar. 



20 



Loads, 
lbs. 

6350 

7350 

7770 



7830 



Deflection, 
in. 

17-32 

5-8 



Remarks 



Failed by concrete crushing around ends of top rein- 
forcing bar. Concrete buckled at the ends of 
top bar. 



2, z Bound Pods. Bent ^, , „ 
a.fno undfiods \ ^£5tirrup5,4wide,No.S0Jcge,l3Jong,IE C.ivC. 

'^^.^ ■,.,«'!« .r. A in'n". - li.— Jy-/'/7in; 



W^ kM"^ 



1 



lO'O" - -■'.r-A'.-i'Oi-^ 



t Stirrups,^ wide, No.BOOage, e''long,tZ'C.lvC. 



S,£ Round Rods 



-Beam 2, Hennebique System. — Length over all, 12 ft. | in.; clear 
span, 10 ft.; breadth, 6\ ins.; depth over all, 8 J ins.; depth to center of 
steel, 71 ins.; vi?-eight of beam, 620 lbs.; mixture, 1:2:4; compressive 
strength of beam, 60 days, 1,747 lbs. per sq. in. 

Steel in tension i .60% 

Steel in compression 



Loads 
lbs. 

1850 
2350 
4350 
5350 
6350 



Total steel 2.40% 

Deflection 

in. Remarks. 

3-32 

1-8 
5-16 
7-16 
9-16 



7650 
8150 
8450 



13-16 

15-16 

1-13-16 



Hair cracks appeared on either side of center, very 
faint. 

Cracks became more general. 

Failed by concrete buckling in center of beam. 



K'/fi 



'a-M K "■ - ■/■•ll lis " >1 



*n 



-k-W """ 


-r.. r T 


Y-^' 


T r T -1 


.y. 


, 


'p ll 


j '"""!•--— i— 


j.-ii-.= 




11 I 


-— 7 


K--//I"->k- 


_ ,.... _ 





-■/o'c" — - 




4s//i''H 



^^,i"ffour?d Bars Bent 



Beam 3, Hennebique System. — Length over all, 11 ft. ii^ ins.; 
clear span, 10 ft. ; breadth, i2|- ins. ; depth over all, 9 ins. ; depth to center 
of steel, 7 J ins.; weight of beam, 876 lbs.; mixture, 1:2:4; strength of 
beam, 60 days, 1,747 lbs. per sq. in. 



Loads, 
lbs. 

2350 


Deflection. 

in. 

1-8 


4350 
6350 


5-32 
3-8 


7950 
8350 
8750 


15-32 
9-16 
7-8 



Remarks. 



First hair cracks appeared in center. 

Failed by concrete crushing at top in center of beam . 



21 

, i'j^'j^ny.'r..'}i.n^?- - - i2\)^ 



f,^i?punaiiMs ^ „ let^' -/f'rl"^r/w'5^.a?.(?fl^f..?:^.w/r_/e::. 



-,4--, r ,> — r -"'• 



J • ' ' ' ' ^ I 1 ■ i —-r u 






g;%i I .-—--- j»,'I^:l:^;at>»^r« --A------ -• =» W-------i-------^Tf^-» .'--i— - ,-it- ;. ,„ 

!£>i' Lf../?^"^- \ <t>5 ~ ■>*/£?- 

Beam 4, Hennebique System. — Length over all, 12 it. ^ in.; clear 
span, 10 ft.; breadth, 6^ ins.; depth over all, 8^ ins.; depth to center 
steel, 7^ ins.; weight of beam, 614 lbs.; mixture, i: 2: 4; compressive 
strength, 60 days, 1,747 lbs. per sq. in. 

Steel in tension i .60% 

Steel in compression 80% 



Loads 
lbs. 


Deflection. 

in. 


1350 


I-16 


2350 


1-8 


3350 


3-16 


4350 
5350 
6350 


7-32 

3-8 

1-2 


7350 
8350 
8650 


19-32 
13-16 

1 



Total 2.40% 

Remarks. 



Faint hair cracks on either side, center very faint. 
Failure by concrete buckling at top in center. 



An average of several tests of the ^ inch round rods used in beams 2, 
3 and 4 is as follows : 

Elastic limit 41,500 lbs; modulus of elasticity 28,000,000; ultimate 
strengh 60,500 lbs.; elongationin 8 inches 25%! reduction of area Oi% ; 
fracture, angular, silky, blueish-grey color: surface pitted and rusty. 



In the space adjacent to the Exhibit building there had been 
planned an elaborate series of test beams built according to the 
various systems in use in this country. Unfortunately, the exhibit 
was completed so late that it was impossible to stir up sufficient 
interest to carry out an elaborate program. Besides, there were no 
fimds available for such experiments, and the expenses connected 
with the tests which were made were very generously borne by the 
Trussed Concrete Steel Co., of Detroit, Mich., and The Henne- 
bique Construction Co., of New York, to whom the writer wishes 
to express his thorough appreciation and thanks for the interest 
taken and the assistance rendered by them in the experiments. 

The tests in question consisted in reinforced concrete beams 
and floor slabs of 1 5 ft. span and a cantilever. Simultaneous with 
the making of the test beams 6-in. cubes were made from the 
concrete which was used in making the beam and floor slabs. 
The results, of these tests are found in Table II, page 16. 



22 

The chatts which were used were a calcareous chert, all of 
which passed a No. lo screen. There are two varieties of chatts, 
a hard silicious chert which comes from Joplin, Mo., and the soft 
calcareous chert which comes from Bonne Terre, Mo. This ma- 
terial is the refuse from the lead mines and as it is relatively 
cheap it is extensively used in St. Louis and vicinity. The chatts 
used was of the calcareous variety and were quite soft and friable, 
having a low compressive strength and therefore making a con- 
crete correspondingly poor. 

It was for this reason that the beams tested failed in many 
cases under a small load before the strength of the steel was de- 
veloped. 

It will be noted that the cinder concrete gave correspondingly 
low results. The cinder was clean and of a better quality than 
is generally used — although it contained a large quantity of 
unburned coal. The strength of the concrete in which it was used 
was about one-half of that of a good stone concrete. The modulus 
of elasticity was about 1,500,000 in the concrete made with chatts 
and 500,000 for the cinder concrete — values materially lower than 
are usually quoted. 

These tests show how important it is to have a hard aggregate 
in order to secure a strong concrete. An important feature gener- 
ally overlooked in tests of concrete is the compressive strength of 
the aggregate itself. If a test of the aggregate was made it would 
serve as a basis for comparing the compressive resistance of con- 
crete and would indicate whether the difference was due to differ- 
ences in the strength of the aggregate or was due to the mixing or 
to character of the other aggregates. 

The concrete for the beams and floor slabs was mixed by hand 
in the proportion of one part Portland cement, two parts Missis- 
sippi River sand and four parts chatts; wooden forms were used 
and were thoroughly wetted before the sloppy wet concrete was 
deposited in them. The concrete was not subsequently wetted 
and the forms were removed at the end of ten days. They remained 
in air, unprotected, and were not handled until tested at the end 
of about 60 days, when they were loaded to destruction with pig 
iron. This method is a slow, laborious process requiring the 
exercise of great care in loading so as to maintain the center of 
gravity of the load over the center of the beam, but there were no 



23 



other means available for testing these beams of such large size 
and span. 

The overturning which occurred in the case of A and B was 
produced by the unequal compression of the earth under the bear- 
ings supporting the beams. Possibly,, this will also account for 
the shearing of the overhanging un-reinforced slab in the T beam 
F. The ground on which the beams were built had been filled 
in with the refuse staff, scaffolding, etc., from the Exposition build- 
ings and in proportioning the bearing area insufficient allowance 
was made for the compressibility of this filling . 

In order to avoid arching of the pig iron, through the deflec- 
tion of the beam under load, the pig iron was placed in piles and 
sufficient clearance was left between the piles so that the deflection 
would not bring them into contact. Where the load required to 
break the beam is large, these piles are quite high (for A and B 
they were 5 ft.), the piling of the pig becomes slower and the 
maintenance of the equilibrium much more difficult as the height 
increases. The rate of loading varied from 50 lbs. to 150 lbs. per 
minute. The deflections were measured at the center from a string 
stretched taut over two wire nails in the side of the beam imme- 
diately over the edge of the support and in the center line of the 
bottom reinforcing steel. 

The following are the results of the tests of these beams : 

Beam F. — Built Sept. 13; tested Dec. i, 1904. Length over all, 
17 ft.; clear span, 15 ft.; breadth at base, 8 ins.; at top, 18 ins.; depth 
over all, 13 J ins.; depth to center of steel, 11 J ins.; reinforcement in bot- 
tom, two I -in. round bars, with one i-in. round bar just above; mixture, 
1:2:4; weight of beam, 2,529 lbs., compressive strength of concrete, 
1,740 lbs. per sq. in., per cent, of steel, 1.63, area of steel, 2.35 sq. ins. 



Time. 


Loads, 
lbs. 


Deflection, 
in. 




Remarks. 


10.50 A. M. 


3656 


3-16 




, 


11-35 " 


6877 


3-16 






11.50 " 


8997 


1-4 






12.00 Noon. 


10807 








1.05 P. M. 


14105 


7-16 






1.40 


18898 


9-16 


Two hair cracks i ft. off center line 








either side 






20166 




Failed. 





Bars sliding as beam collapsed, Fig. 7. The slab sheared off on 
one side as will be seen, this was probably due to lack of uniformity of 







^iz'-y 


^. ,cr' r," ^ ^ ^ 


n 

<-/2> 




f— > A 



Beam A 



'x ^\ X '^v X — =iii-. \ \ 






/ / 






<--/2->|<- 



-15' O 



Beam B. 



-><-/2-> 






\ '^N \ \ ^N ^V X'^^e^^^--^^ \ / ^L^^---^-="f' y / / / / 



/ 



<-/2"^- 



--I5 

Beam C. 



—--><- 12 > 



=---^^^. 



\ \ ^. \ \ ^. \ \^ 



/ ^zsx*--^7^ / / / / / / / 



t.-zz=:ye=.z.-zinrr--.3i^---jtitr-s-jifsz.-z:^ 



k/2 



-j^ 



--IS' o~ 

Beam D. 



-4;- 12^ 



<- }Z%- 



15' 0-- 

Beam E, 



->k-/2'V 



</2 



% 



-15 O 



— ->^/2 ^ 



Beam F. 



K--7^'->l 






I'f 

.■k. iL' 

»-- -/g 



V-I'4'A 



iii 



m^:^4- 






a 



H/&'^ 



My. 



I'O" 
-^- ll' 



K/^'H 






'7^ 



Y-J'O'^ 



'//AM I'O' 



I W\ ' 10" 
4"'/" r'^ 

■■■5'8- ' 



^- 



<9^<- 



-16' 6-- 



Ens. Hews. 



-^f^? 



pJI 



\ \ \ \ \ \ \ \ ^ / / / / / / / A mnpipnnpX. 



j<--/'4"->l<-/'^">;vS 



Fig. 8. — Diagrams of Test Beams and Floor Slab Showing Dimensions and Reinforcement. 



25 

load. The bars did not slip until the beam collapsed There was no 
reinforcing in the slab. The dimensions of beam and other information 
can be obtained from Fig 8, page 24. 

Beam E. — Built Sept. 13; tested, Dec. i, 1904. Length over alU 
17 ft.; clear span, 15 ft.; breadth, 12 ins.; depth over all, 13I ins.; depth 
to center of steel, 12 ins.; weight of beam, 2,677 lbs.; mixture, 1:2:4; 




Fig. 7. — View of^End of Beam E Showing Shearing Off of Slab and 

Sliding of Reinforcing Rods. 



compressive strength of concrete, 1,740 lbs. per sq. in.; reinforcement in 
bottom, three i-in. round bars 17 ft. long; area of steel, 2.35 sq. ins.; 
per cent, 1.63. 



Remarks 

Deflection not noticed before 1,000 lbs. 



. :me. 


Loads, 
lbs. sq. in. 


Deflection, 
in. 


9.00 A. M. 


16510 


9-32 


12.00 Noon. 


20166 


11-32 


5 30 P- M. 


24612 
26460 


15-32 
1-2 



26 



Time. 


Loads 
lbs. s-q. in. 


Defection 
in. 


Dec. 2d. 






8.30 A. M. 


33^98 


21-32 


S.30 " 


26460 


II-16 



Remarks. 



Two hair cracks, one on either side of 
the center line. 
33108 Failed. 

A series of vertical cracks appeared iintil the beam failed suddenly 
by horizontal shear at one end entirely. Bars again slipped as beam 
collapsed. Dimensions of beam given in Fig. 8, page 24. Fig. 9 shows 
beam after failure. 

Dimensions, etc.. see Fie. S. 




Fig. 9. — View of End of Beam E Showing Sliding of Reinforcement. 



Beam D. — Built Sept. 13; tested. Dec. 2, 3, 1904; Length over all, 
17 ft.; clear span, 15 ft.; breadth, 12 ins. ; depth over all, 13^ ins.; depth 
to center of steel. 12 ins.; weight of beam, 2,677 lbs.; mixture, 1:2:4; 
reinforcement in bottom, two J-in. Kahn bars 17 ft. long; reinforcement 
in bottom, one f-in. Kahn bar 9 ft. long, bent up slightly; area steel in 
tension, 2.34 sq. ins.; per cent, of steel, 1.63; compressive strength of 
concrete, 1,740 lbs. per sq. in. 



27 



Time. 
Dec. 2d. 
3.30 P. M. 

3-50 
5.00 " 

S.30 " 
Dec. 3d. 
8.30 A. M. 

8-55 

9-30 
10.30 
11.30 

11.45 
11.50 



Loads, 
lbs. 



6479 

8461 

11806 

15033 

15033 
2073? 

23476 
27800 
30719 
32663 
32663 



Deflection, 
ins. 

I-16 

3-32 

1-4 

11-32 

11-16 

3-8 

1-2 
11-16 
I in. 
if in. 



Dimensions, etc., see Fig. 8. 



Remarks. 



Failed slowly 4 ft. 6 ins. from each end 
of beam. 



Beam C. — Built Sept. 12; tested, Dec. 3, 4, 5, 1904. Lengtn over 
all, 17 ft.; clear span, 15 ft.; breadth, 12 ins.; depth over all, 13I ins.; 
depth to center of steel, 12 ins.; weight of beam, 2,677 lbs.; mixture, 
1 : 2:4; reinforcement in bottom, two f-in. Kahn bars 1 7 ft. long; reinforce- 
ment in bottom, one f-in Kahn bar 9 ft. long, bent up slightly; reinforce- 
ment in top, two i-in. Kahn bars 9 ft. inverted ; area of steel in tension, 2.34 
sq. ins.; area of steel in compression, .76 sq. in.; total area of steel, 3.10 
sq. ins.; per cent, of steel, 2.15; compressive strength of concrete, 1,740 
lbs. per sq. in. 



Time. 


Load, 
lbs. 


Deflection 
ins. 


Dec. 3. 






3.10 P. M. 

3-50 " 
4.20 " 

Dec. 5. 

Dec. 6. 


5629 1-32 
II398 3-16 
15287 3-8 

Nothing done. , 


8.00 A. M. 


15287 


3-8 


8.30 " 


18100 


3-8 


9.00 " 


21688 


15-32 


9-30 " 


24058 


5-8 


9-55 " 
10.05 " 


29943 
28934 


7-8 

I 


10.10 " 


29914 


li 


10.15 " 


30878 


1-11-16 


10.25 " 







Remarks. 



Sunday. 



Hair cracks appearing. 



Failed. 
Dimensions, etc., shown in Fig. 8. 



28 



Beam B. — Built Sept. 12; tested, Dec. 5, 6, 1904. Length over all, 
17 ft.; clear span, 15 ft.; breadth, 16 ins.; depth over all, 17^ ins.; depth 
to center of steel, 16 ins.; reinforcement in bottom, two i-in. Kahn bars 
17 ft. long; reinforcement in bottom, one f-in. Kahn bar 9 ft. long, bent 
slightly upwards; area of steel, 3.62 sq. ins. or 1.41%; weight of beam, 
4,600 lbs.; mixture, 1:2:4; compressive strength of concrete, 1,740 lbs. 



per sq. m. 



Time. 


Load, 
lbs. 


Deflection, 
ins. 


Dec. 5. 






2.00 P. M. 


10417 


I-16 


2.30 " 


15189 


3-32 


3.20 " 


22802 


7-32 


4.10 " 
4-45 " 


27607 
31487 


9-32 
11-32 


Dec. 6. 






8.30 A. M. 


31487 


11-32 


9-35 " 
10.50 " 


33403 
38190 


11-32 
11-32 


12.45 P- M. 


45082 


15-32 


I-30 " 


47817 


3-4 


2.10 " 


50000 


7-8 


3.10 " 


54735 


1-11-32 


3-50 " 


55727 
56712 
57696 
58675 


I- 7-16 
1-19-32 
I— 11-16 
1-3 1-32 


4.15 " 


59906 


2 


5.00 " 


60911 


2-11-32 



Remarks. 



One hair crack on bottom of beam 
under each bent bar. 



Two more hair cracks appeared. 



Two more hair cracks appeared nearer 
bearings. 



Beam overturned. 



Dimensions, etc., see Fig. 8. 



Beam A. — Built Sept. 13, 1904; tested, Dec. 7-14, 1904. Length 
over all, 17 ft.; clear span, 15 ft.; breadth, 16 ins.; depth over all, 17^ 
ins.; depth to center of steel, 16 ins.; reinforcement in bottom, two i-in. 
Kahn bars 17 ft. long; reinforcement in center, one f-in. Kahn bar 9 ft. 
long, bent up slightly; reinforcement in top, two f-in. Kahn bars 9 ft. 
long, inverted; weight of beam, 4,600 lbs.; mixture, 1:2:4; area steel in 
tension, 3.62 or 1.41%; area steel in compression, 1.56 or .60% ; total 
steel, 5.18 or 2.10%; compressive strength of concrete, 1,740 lbs. per sq. in. 



Time. 


Loads, 
lbs. 


Deflection. 

in. 


Dec. 7: 






9.25 A. M. 






I0.4S " 


IO168 


I-16 


11.40 " 


15937 


3-32 



Remarks. 



Started. 



29 





Loads. 


Deflecti 


Time. 


lbs. 


in. 


2.25 P. M. 


20769 


5-32 


3.10 " 


25632 


3-16 


3-25 " 


27617 


3-16 


3-55 " 


31548 


3-16 


4-30 " 


33561 


3-16 


4-45 " 


35477 


7-32 


5.00 " 


37458 


7-32 



Remarks, 



Two faint hair cracks, one at each end of 
bent bar in center; beam started to 
overturn, bearings sinking unequally. 
Dec. 8: Unloaded and straightened. 

No deflection observable, then began loading. 
Dec. 9: 



Four hair cracks (2 more) on each side 
of center. 

Rain stopped, loading beam over- 
turned, due to unequal settling of 
foundations. 



8.30 A. M. 


37458 


7-32 


9-45 " 


40839 


7-32 


0.35 " 


44723 


1-4 



11.25 



Dec. 



II 



50000 



52693 

52962 

54945 
60856 



5-16 



3-32 
13-32 
5-8 



Set in beam. 



Beam overturned. 



Foundations again settling unequally, beam straightened, one hair 
crack in center, 2, 3 ft. 6 ins. on either side of center of beam; |-in deflec- 
tion set in beam. Foundations releveled bearing area increased and beam 
reloaded. 

Dec. 12: Sunday — Nothing done. 
Dec. 13: 
II. 15 A. M. 60856 3-8 Set in beam. 

Several hair cracks from top ^-in. opening traveling off in both direc- 
tions horizontally, middle each SJ ins. from top. 

6381 1 Two more hair cracks appeared on 

either side of center line. 



Remarks 



Time. 


Loads, 
lbs. 


Deflection 
in. 


.45 P- M. 


66021 

74941 
75000 


3-4 
1-1-8 



One crack 18 ins. from center line, 9 

ins. from top. 
One crack 36 ins. from center line, 11 

inches from top. 
One crack 56 ins. from center line, 7 

inches from too. 



5.00 P. M. 80000 1-3-8 



3<» 



Time. 


Loads. 
lbs. 


Deflection 
in. 


Dec. 14: 






8.00 A. M. 


80000 


1-3-4 




81010 


1-13-16 




82005 


1-13-16 




83005 


I- 7-8 




83977 


I- 7-8 


11.30 A. M. 


85400 


I- 7-8 


12.00 Noon. 


87385 


2- 1-32 


1.25 P. M. 


90362 


2- 5-8 


215 " 


93269 


3- 1-8 


2.30 " 


94074 


3- 5-16 


2.40 " 


94512 




Weight beam 


4600 




Total load. 


991 T2 





RenaarVs. 



Failed 




Fig. 10. — View of Kahn Beam A Under Load 



Kahn System Hollow Tile Floor Construction. — Built Sept. 
21, tested Nov. 30, Dec. i, 2, 1904. Length over all, 18 ft. Clear 
span 16 ft. 6 ins. Width, 5 ft. 8 ins. Depth, 10 ins. Tile, 
10 X 12 ins. Beam joists, five, 4 x 10 ins., 18 ft. long, i' 4" centers. 



31 

Reinforcement, each joist, one |-in. Kahn bar, i8 ft. long. 
Mixture, 1:3: 5. Area steel, each joist, 0.78 in. or 2.30 per 
cent. Weight of slab, 5,800-lbs. 




Fig. II. — View of Kahn Hollow Tile Floor After Failure. 



Time. 


Loads, 
lbs. 


Deflection. 
ins. 




Nov. 30: 








4.10 p. M. 


12457 


n. 3-32 s 


3-32 


4-45 " 


18300 


1-8 


3-32 


5-IO " 


22200 


1-2 


3-8 


530 " 
Dec. I : 


25132 


5-8 


3-8 


8.30 A. M. 


25132 


3-4 


9-16 


5-30 " 
Dec. 2 : 


25132 


3-4 


21-32 


8.30 A. M. 


25132 


3-4 


23-32 


11.25 " 


25132 


25-32 


3-4 


11.50 " 


34634 


2-1-2 





Remarks. 



actly. 



Two vertical cracks appeared 
3 ins off center line on either 
side. 



32 



11.55 A. M. 35611 Concrete commenced to crush 

on top over last cracks loading stopped, beam kept cracking and slowly 
deflected until it failed at 12.15 (20 minutes) with center cracks opening 
up and another 7 ft. off centre line concrete at center crushing out and a 
crack running along line of steel from center to right three feet. Breaking 
load 500 lbs. per sq. foot. The dimensions of slab are shown in Fig. 8, 
page 24, Fig. 11 shows floor after failure. 



Siegwart Floor. — ^Length over all 14 ft. 3 J ins., clear span 
13 ft. 5 J ins., depth 6 ins., width of slab 2)Z i^s. 





6" 








lA'"^ ' " - -J 






r 






IF^ 


^^.|.^.^ 




\ 








X b / 
nsome Nods-'' 


<4|'^— 


/j'i-i"- 4^i> 




Time. 




Loac 
lbs. 


Deflectior 
in. 


. 


Remarks. 


8.30 A. M. 




2901 


1-8 






9-iS " 




5484 


5-16 






9-25 " 




8409 


1-2 


Hair cracks 


well distributed 










bottom beam. 






1037J 


\ 13-16 










1136^ 


) 7-8 






10.05 ** 




1531: 
1628^ 


1 1-23-32 
\ 2-3-4 






10.15 " 




1683] 


[ 


Failed. 







along 



This floor slab was composed of beams made according to 
Siegwart System ; in above sketch the slab is seen to be composed 
of three slabs 11x6 ins. in section, and reinforced with rods ac- 
cording to Hennebique System without shear straps. The beams 
are cast around cores (core openings shown in sketch), the steel 
being placed in position and the concrete cast around it; the cores 
are withdrawn and the beams feathered apart at the points indi- 
cated. These beams were made in New York, and were shipped 
by express when 60 days old to the exhibit, where they were placed 
in position and the joints grouted. A load of bags of sand was 
placed on the floor (100 lbs. per sq. ft.) and remained there until 
the close of the Exposition, when it was loaded with pig iron to 
destruction, the beams being about 6 months old. The idea of 
this system is to make the beams for certain loads and spans and 
carry them in stock as steel I-beams are carried, shipping on order. 

Cantilever. — This is shown in Fig. 12 and was built to illustrate 
the flexibility of reinforced concrete, the dimensions and rein- 



33 

forcement are shown in Figs. 13, 14 and 15. The stairway hung 
free and led to the top which was a walk; this was in service 
during the Exposition. 




Fig. 12. — View of Reinforced Concrete Cantilever Tested to Destruction. 

The cantilever was built, as was discovered afterwards, over 
a wooden box drain and the settlement of the foundation caused 
the cantilever to tilt towards the outer end. 



H ■-.-;, — 330'- - - - 

J m^i k - - zd'o'- 




EM6. ^EM I , . I , , I ! F/Uec/ 6round 

i^^"'- }<•■"■ ^5'0"- >f:-30--^ ll'0—\ - >l 



Side Elevation. 
Fig 13 



M 



The forms, instead of being removed gradually, were quickly 
removed, and the sudden apphcation of the load caused a strain 



■^'0'^- 




End Eleva+ion, North. 



Fig. 



14. 



which cracked the cantilever at the shank on the left-hand side. 
The props were restored and the cantilever washed with neat 

9 Rocfs, §"Diam.'., 



4Bun(iles\ 
g D/am. ) \ 



, :::::'. ?. :: :. :\ , . ,■ 






/// ^/// '//^ ////// /// ^ // / 



9Roc:ls,§"Diarn. 



_ j^ 



-> 



■6Ro'cis,i"Diarrk 



Sec-rion 
Fro 



A-B. 
IS 



35 



cement. The props were then gradually removed and the canti- 
lever remained unchanged until tested with pig iron. The applica- 
tion of this load caused the cracks to open at left side of shank and 
the cantilever collapsed. As bars of the requisite size were not 
available a bundle of smaller rods w^as substituted; the shear 
members were insufficient to hold the cantilever and it pulled 




Fig. 1 6. — View Showing Failure of Reinforced Concrete Cantilever 



apart at the left shank and failed as shown in Fig. i6 before the 
compressive resistance of the concrete in the right center section of 
the shank had been reached. The loading was as follows: 



Loads, 
lbs. 


Deflection, 
in. 


3060 


I-16 


9845 


1-4 


13735 


11-32 


14760 




17680 


1-8 ( 


2 0607 





Remarks 



Hair crack appeared. 

Opening at center 11-16 in. at outer end. 

Failed 4-11-16 in. extension at the center. 



Besides these, tests were made of cement shingles, concrete 
sewer pipes, cement bricks and hollow blocks. 



36 

The Collective Portland Cement Exhibit and Model Testing 
Laboratory was assembled with a view of exploiting the American 
Portland Cement Industry and not with a view of advertising any 
particular process, plant or product. It was highly beneficial in 
disseminating a better knowledge of the proper methods of testing 
and of the nature, uses and properties of Portland cement ; and 
in recognition of this fact it received two grand prizes, the highest 
awards of the Exposition.* 

It is to be regretted that the time available for the experimental 
work was not longer, so that much more data could have been 
obtained. 

It is, however, a matter of gratification to all those connected 
with this exhibit that the work thus started will be continued under 
the direction of the United States Government, the Joint Com- 
mittee on Concrete and Reinforced Concrete, and other inter- 
ested persons, and it is to be hoped that the exhaustive series of 
investigations of structural materials which have been planned 
under the direction of the National Advisory Board on Fuels 
and Structural Materials may be successfully carried out thereby 
supplying information of inestimable value to the engineering 
profession. 

*The Collective Portland Cement Exhibit was awarded a Grand Prize (see page 2 
The Model Testing Laboratory received a second Grand Prize. 



LIBRARY OF CONGRESS 



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